The present invention relates to a plug of a fiber optic cable connector used in optical communication equipment.
A conventional plug of a fiber optic cable connector is arranged, as shown in FIG. 1 (see PZN47255 described in Siemens' catalog "Fiber Optic Components Reliable Partners of Electronics", and U.S. Pat. No. No. 4,190,317). Referring to FIG. 1, reference numeral 1 denotes a cylindrical locking nut; and 2, a ferrule or pin fixed inside the nut 1.
In order to connect a fiber optic cable having a distal end with a plug of a structure shown in FIG. 1, the ferrule 2 of each plug is inserted into an adapter (not shown) or receptacle (not shown) such that end faces of optical fibers (not shown) abut against each other. Threads formed on the inner surface of the locking nut 1 are mated with those formed on the outer surface of the adapter, and the locking nut 1 is rotated.
In a conventional plug of a fiber optic connector, when two plugs are inserted from both ends of an adapter to connect the optical fibers inside the plugs, the rotating degree of the locking nut 1 of the plug is not accurately determined with respect to the adapter. The locking nut 1 is often excessively rotated to cause the locking nut 1 to generate an excessive rotational torque between end faces of the ferrules 2 upon connection of the optical fibers. As a result, the ferrule 2 collides against the adapter and the end face of the optical fiber fixed on an axis of the ferrule are damaged to degrade fiber connecting reliability.